Clinical and prognostic significance of molecular studies in cutaneous T-cell lymphoma.

Abstract

Mycosis fungoides is the most common form of primary cutaneous T-cell lymphoma (CTCL) and is typically characterised by four cutaneous stages of disease, as described by Bunn and Lamberg [1–3]. In early stages of mycosis fungoides the histological diagnosis can be difficult, and although immunophenotypic studies have helped to distinguish rarer subtypes of primary cutaneous T-cell lymphoma from mycosis fungoides [4], such approaches have not helped in the diagnosis of early-stage disease. While patients with early patch- and plaque-stage disease may have a normal life expectancy, some patients develop tumours or progress to the erythrodermic stages of the disease. Such patients have a median survival of 5 years; the presence of peripheral blood or partial/total lymph node effacement is associated with a poorer prognosis and a median survival of 2.5 years [5]. Significant visceral involvement is usually apparent only in patients who have fulminant disease. Sezary syndrome is characterised by erythroderma, peripheral lymphadenopathy associated with intense pruritus, and the presence of characteristic Sezary cells within peripheral blood. Although most patients with Sezary syndrome have a history of an “eczematous eruption” prior to a diagnosis of cutaneous T-cell lymphoma, some patients with mycosis fungoides gradually develop erythroderma and clinical features indistinguishable from Sezary syndrome. Other independent prognostic factors in mycosis fungoides include age (> 60 years) at presentation, which presumably reflects a poorer host immune response in the elderly [6].